Piston



Jan. 5 192s. 1,568,547

W. R. DAY

PISTON Filed Dec. 15V, 1924 WQ( mw Patented Jan. 5, 1926.

yUNITI-:D STATES WILLIAM n. DAY, or CLEVELAND, omo.

' rIs'roN.

Application led December 13, 1924. Serial No. 755,609'.

To all whom t 71mg/ conce'mil' A Be it known that .-I, WiLLIAM R. DAY, a citizen-.ofthe United States, residing in Cleveland, county of Cuyahoga, and State of Ohio, have invented a new and useful Improvement in Pistons, of which the `following is a specification.

My invention relates to the construction of istons.

ne of the objects of my invention is a light weight piston.

Another object is to eliminate distortion of the bearing portion of pistons.

Another object is a piston which wears the wall of a cylinder evenly.

Another object is to eliminate the scoring of the cylinder wall.

Another object is to prolon the life of pistons as well as of cyllnders 1n which the pistons operate.-

Another object is avpiston of low cost of production.

It is well 4known in the art that a iston should be as light yin weight as possib e and should create as little. friction as possible whenit operates in a cylinder.

It isl also Well known in the art that certain portions of the usual pistons wear much faster than other portions, indicating thereby that too much friction is create by these fast wearing portions.

To-eliminate, or at least mitigate, this friction, 'the pistony shell has, previously,

4 been relieved or slit but such expediences not only reduce the area ofthe bearing surface of the iston but also add materially to the cost of) production of the piston.

, When these portions are relieved, ,the bearing surface of the piston is unequally distributed, thereby vvcausing the cylinder wall to wear uneven and out of round and guite frequently s corethe cylinder because oreig'n matter can readily and easily wedgev onto the bearing surface from these relieved portions; all'of which causes a lea piston and other disadvantages in a short time.

After experimentation, I have found that the action of the rod, particularly connect# ing rod or pitman, exerts unequal pressure on the piston throuofh the piston-pin bosses and that the shell ofD the piston, as previously made, is thereby distorted t0 such an ex-` tent that some portions of this shell are forced against the cylinder wall harder than other portions, thereby'causing the trouble mentioned. i

`ton at less cost than PATENT OFFICE.

Upon further experimentation, I have found that the shell of a piston is not so distorted when the boss or bosses, by means of which the piston is connected to the rod,

HEISSUED is as free as possible from the shell of the piston.

Therefore, lby elim'inatin as far as possible, any connection of t e boss and the shell, I eliminate the distortion of the shell `as well as the cost of correction of these distortions, thereby roducing a better pis- Iheretofore.

Andl furthermore, I -provide abru t shoulders where the bearing portions of t e shell join the relieved' portions thereof, thereby eliminating thev scoring of the cylinder.

One structure for attaining my objects and embodying the features of my invention is illustrated in the accompanying drawing in which Fig. 1 is a perspective view of a piston embodying my invention and showing the general appearance'of the piston as a whole.

Fig. 2 1s a partial section, taken on a vertical plane indicated by the line 2-'2 in Fig. 1, showing clearly the relation of the pistonpin bosses to the shell of the piston and to the wall of the cylinder.

Fig. 3 is -a partial section, taken on a vertical plane indicated by the line 3-3 in Fig. 1, showing clearly the relation of the connecting portion and the bearing portions of the shell.

Fig. 4 is a section, taken on a horizontal plane indicated by the line 4 4 in 'Fig. 1, showing the horizontal relation between the piston portions.V v

Similar reference characters refer to similar parts throughout the views.

The piston shown in the accompanying drawin is composed, principally, of the upper aring portion A, the` lower bearing portion B, the connecting portions C, and the bosses D. f n The upper bearing portion A Wall 9 of the cylinderv all around vand is closed at the top by the Wall 10 and is provided with fthe grooves 11 for piston rings as usual in pistons.

lits-the' I It is observed that 'the circumferential is forl the purpose of providing more'bear-v A f ing surface on vthose sldes of the portion where the usual connecting rod exerts an `angular pressure on the piston, thereby pro- -both of them and connects them to each other. The longitudinal ribs 15 arev provided to stiffen the portions C as well as the piston as a whole.

It is observed that the outer circumferential surface 16 of each portion C is disposed below the outer circumferential surface of the portions A and B and that the shoulders 17 and 18 are abrupt; the purpose thereof will appearpresently.

Each of the bosses D has the bore 19 for a piston-pin or for a bushing therefor. Each of the bosses D is supported on the portion A and is free of any connection with the portion B.

Each of the bosses D is connected to the portion A by the circumferential rib 20 extending upward and merging into the portion 13 and by the two radial ribs 21 extending upyvard and merging into the wall 1 0 and into the rib 20. Thereby providing a substantial support for each of the-bosses D without connecting them to the portion B and carrying the main point of such support up to the wall 10 so 4that most of the unequal stresses brought on the bosses D are transmitted to this wall 10 and to the stiffer wall of the portion A without materially effecting either of the portions A and B.

I prefer to use the two radialribs 21 as shown to more effectively counteract the distortive action on the bosses D and to transmit'as much as possible of the stress caused by the action o the connecting rod on the bosses directlyA to the top wall 10 of thev iston. This two rib arrangement also stiifns the ribA 20 and thereby prevents this distortive effect from being transmitted to the bearing rtions of -the piston.

It is o rvedV that the outer circumferential surface 22 of the rib 20 is disposed below ythe outer circumferential surface of the bearing portions A and B and that the shoulders 23 are abrupt similar to the shoulders 18 and 17 previously described.

These abrupt shoulders on the portion A have a tendency to scrape the surplus lubricant oif of the wall of the cylinder on the down stroke of the piston. A certain quantity of this scraped off lubricant adheres to these shoulders during this down stroke and is deposited again ou the' cylinder wall op the upstroke. Some of this scraped olf lubricant also travels downward on the ribs 2() and finds its way onto the piston-pin and thereby helps to lubricate the same. Some of this scraped off lubricant also travels downward on the portions C and thereby helps to lubricate the portion B. When too much vlubricant is splashed or otherwise put on the cylinder Wall, the shoulders 23 and 17 scrape it olf on the downstroke while the shoulders 18 scrape it off Von the up stroke. In either cascof such scraping olf, the surplus lubricant finds its way into the interior of the piston and drips off into the crank case or elsewhere.

The above shoulder arrangement prevents excessive lubricant from entering the cylinder above the piston and thereby economizcs in lubricant consumption as well as aiding in the efficiency of the power development of the engine and at the same time adequately lubricate the cylinder wall.

IThese abrupt shoulders -also effectively scrape all foreign substances from the cylinder wall, similar to the scraping process just described, thereby preventing the scoring of the cylinder.

The manner of supporting the bosses D on the piston, as set forth, prevents the connecting rod, or other rod, acting on these bosses from distorting the bearing portions of the piston and therefore, such a piston requires no relieving or otherV expediencies and the surfaces 16 and 22 need no machining.

In the elimination of this relieving and Vmachining, augmented by the light weight.

structure possible with my invention, and further augmented by the saving in lubricant and by increased power, I provide a piston which is very economical of production and very efficient in operation and in action.

The wide surfaces 12 adjacent the narrower surfaces 13, bot-h of which surfaces bear o n the cylinder wall, al1 around, wears the cylinder wall evenly and therebyl prevents' leaky pistons and prolongs the 'fe of the cylinderas well as of the piston.

I am aware that modifications may be made in the structure of the piston as well as in thel arrangement of the elements thereof; therefore, without limiting myself to the precise construction and arrangements shown and described,

I claim 1. A piston comprising, an upper bearing portion, a lower bearing portion spaced from said upper bearing portion, twonarrow portions connecting said upper and lower bearing portions, piston-pin bossesintegral with said upper bearing portion, and said bosses free from said lower bearing portion to prevent the distortion of said lower bearing portion when said bosses are 20 3. A piston comprising, an upper bearing distorted by a piston-pin extending through said bosses out of alignment with elements co-operating with the piston-pin.

f 2. A piston comprising, an upper bearing portion closed by a top wall, a lower bearing portion, connecting portions-between sai upper and said lower bearing portions, piston-pin bosses disposed intermediate of said connecting portions and free 'from said lower bearing portion, rib means connecting each of said bosses to said upper bearing portion, and the outer surfaces of said connecting portions and of said rib means below the outer surface of said bearing portions and 4defined by abruptr shoulders to lubricate the wallof the .cylin der in which the piston operates without permitting excessive lubricant to enter this cylinder above the piston.

connecting each o f saidbosses to said upper i portion closed by a top wall, a lower 4bearin portion, connecting portions between sai upper and said-lower bearing portions,'pis ton-pinbosses disposed intermediate of said connecting portions y and free from saidv lower portion, said upper *bearing portion wider above said connecting portions than above said piston bosses to lcompensate lfor angular pressure on the piston, rib means WILLIAM R. DAY. 

